Supervisory Control and Data Acquisition (SCADA) Communication

SCADA Communication is a core component of a Monitoring System.

SCADA communication can happen in a number of ways. Early SCADA communication took place over radio, modem, or dedicated serial lines. Today, it is much more common for SCADA communications to travel over LAN or SONET.


The process of communication over a SCADA system involves several different SCADA system components. These include the sensors and control relays, RTUs, master units, and the overall network.

Smarter RTUs make your SCADA set up easier.

Each of these parts are needed for good SCADA communication. A system can monitor alarms and status updates within the network only when all of the underlying components function well. For more complete monitoring of SCADA communications, you can use smarter RTUs with special processing abilities.

The RTU is where most SCADA is grouped in the system. Values from inputs and outputs, referred to as SCADA points, are sent from single sensors to the RTU. The RTU is tasked with sending these SCADA notes to the master station, or HMI.

The HMI Translates SCADA into a Human-Readable Form.

The HMI is the component of the SCADA communication system that takes all of the data from the RTUs across the network. The it converts it into a form that is readable by humans. Network staff examine the SCADA communications in the sorted HMI view. With good situational awareness, they can respond to network alarms appropriately.

SCADA can contain sensitive data, so it is important to use secure LAN networks when transmitting data to RTUs and the master station. However, LAN can cost a lot to install at remote sites, and it may not be feasible for an company to immediately join all of their remote sites into the LAN network. What's most important is knowing the risks in your industry and having a good security plan.

NetGuardian Offers for Many Types of SCADA Communication.

Using NetGuardian 832A RTUs gives you the ability to switch out your SCADA system slowly. They support older transports like serial (RS232 or RS485), but also support LAN. This means that you can transmit SCADA communication over the LAN as your network expands outward.

The NetGuardian is designed to talk over several connection types (LAN, serial, and dial-up). This allow you to simply switch your RTU device to the LAN port when LAN is available at your site. This provides a cost-effective communication solution. You can then expand LAN over several billing cycles while still using your existing SCADA communication equipment.

Resources Related to SCADA Tutorials:
SCADA Tutorial White Paper.

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